The cost of injury is considerable, estimated at $260 billion for fiscal year 1995. The primary costs are morbidity costs -- the value of goods and services not produced because of injury. Preliminary findings indicate that psychological distress is a significant predictor of post-injury disability and that symptoms of depression often accompany injury, appearing out of proportion to the severity of physical injury. The purpose of this study is to follow up on these findings, and in particular, to examine the public health impact of the development of major depression following minor injury. The majority of all injuries are minor, defined as injuries of sufficient import that individuals seek urgent medical care in an emergency department, but which do not threaten loss of life or limb. The primary aims of this study are to: determine the frequency of major depression (& related mood disorders) following minor physical injury; and determine the extent to which developing major depression (& related mood disorders) contribute to increased disability and reduced quality of life following minor physical injury. The secondary aims are to: compare the effect of developing depression and related psychiatric disorders (anxiety & stress-related disorders) on outcomes following minor physical injury; and describe the onset and course of developing depression and related psychiatric disorders in the year following minor physical injury. 250 patients presenting to the emergency department at the Hospital of the University of Pennsylvania with minor injury will be enrolled. Minor injury will be defined by the Injury Severity Score for anatomic severity and the triage-Revised Trauma Score for physiologic severity. Intake information includes injury data, pre-injury disability and quality of life. A comprehensive, structured psychiatric diagnostic evaluation will be conducted 72 hours after the minor injury has occurred, documenting psychiatric baseline (excluding patients with existing depression at time of injury or major DSM IV Axis I psychotic disorders). Participants will be followed by systematic, longitudinal follow-up evaluations (3, 6, & 12 months) to determine the development of major depression and its effect on post-injury disability and quality of life. The quasi-experimental design, in which each participant serves as his/her own control, will enable an accurate and comprehensive profile of developing major depression (and related mood disorders) following minor injury. Further, this design, using comprehensive psychiatric evaluation, will allow a critical analysis of the influence of major depression and related psychiatric disorders on outcomes following minor injury.